Haematologica 2004;89: supplement no. 8 - Supplements ...

XVIII Congress of the Italian Society for Hemostasis and Thrombosis Research, Rome, Sept. 30-Oct. 3, 200437od was 106 days (range 30-323 days). In 20 patientsALN filters were not removed for different clinicalreasons. ALN filter offers a broad range of clinicalapplications; it can be used as a definitive filter or itcan be safely removed after a medium term periodof placement, whereas retrieval after 3 months canbe unsuccessful. Indications for retrieval and maximumimplantation time require further studies.CO-036LMWH OR XIMELAGATRAN VERSUS VKA IN THE PREVENTIONOF VTE AFTER MAJOR KNEE SURGERY: A META-ANALYSIS OFRANDOMIZED CONTROLLED TRIALSIorio A, Ferrante F, Conti S, Nenci GGSezione di Medicina Interna e Cardiovascolare,Università di Perugia, ItalyIntroduction: Low molecular weight heparins(LMWH) have shown a better efficacy and safety profilethan UFH and are the most commonly used prophylacticagent in Europe after orthopedic surgery.On the contrary, vitamin K antagonists (VKA) still havethe preference of surgeons in North America for kneereplacement. This is likely to be due to the higher rateof bleeding at the surgical site for LMWH than forVKA, particularly if heparin is started soon aftersurgery or even before, and this in spite of the higherrate of VTE occurring with the use of VKA as prophylacticagent. Moreover, the new thrombin inhibitorXimelagratran has also been recently compared toVKA in knee surgery. Aims: To perform a meta-analysisof the randomized controlled trials evaluatingsafety and efficacy of VKA in comparison to LMWH orximelagatran in the prevention of venous thromboembolismafter major knee surgery. Materials andmethods: Searches of MEDLINE and EMBASE wereperformed. The analysis was performed on venographicallyevaluated patients. Standard metanalytictechnique was applied. Results: Nine studies (6 withLMWH and 3 with ximelagatran) were included in theanalysis for a total of 10291 patients (5033 and 5258,respectively). Statistical heterogeneity was found onlyfor symptomatic PE. For total DVT, VKA resulted lesseffective than LMWH (RR of 1.32 [1.18 – 1.47], P